This invention generally relates to grinding wheels, and is specifically concerned with a grinding wheel assembly for grinding and laterally sizing elastomeric power transmission belts.
Grinding wheels for grinding and sizing elastomeric belts are known in the prior art. Such wheels generally comprise a wheel member having an outer surface which includes a plurality of v-shaped valleys and peaks that are covered with an abrasive coating. A pair of opposing annular flanges is integrally formed on the side surfaces of the wheel member that radially extend beyond the abrasive outer surface of the wheel member. The same type of abrasive coating which overlies the outer surface of the wheel member is applied to the inner sides of the flanges. Additionally, the outermost portion of each of the flanges includes a tapered lead-in. In operation, the tapered lead-ins of the opposing flanges receive an elastomeric belt to be ground and sized. The abrasive coating on the inner sides of the flanges trims the belt to a specific width, while the outer surface of the wheel grinds the inner surface of the belt into a peak-and-valley pattern complementary to that on the outer surface of the wheel member.
While such prior art grinding wheel assemblies are generally adequate for their intended purpose, the applicants have noted two areas where the operation of such grinding wheels could be greatly improved. First, the applicants have observed that the swarf or grindings generated by the cutting operation tend to accumulate and compact between the sides of the elastomeric belt and the inner surfaces of the flanges of the wheel assembly. The accumulation and compaction of such grindings interferes with the cutting operation on the sides of the belt, and can result in an improper lateral sizing of the belt. Worse yet, the large amount of friction created by such an accumulation and compaction of grindings can not only slow production, but actually burn the sides of the elastomeric belt. While the space between the sides of the belt and the inner surfaces of the flanges can be regularly cleaned to prevent such a harmful build up of grindings, such cleanings lower productivity by increasing downtime. Second, because the abrasive coating on the inner side surfaces of the flanges must work relatively harder than the abrasive coating on the outer portion of the wheel due to the relatively heavier grinding load applied thereon, these coatings tend to wear out well before the abrasive coating on the wheel member. Such an uneven wear pattern necessitates more frequent refurbishings or replacements of the wheel than would be the case if wear on all of the abrasive coatings were uniform.
Clearly, there is a need for an improved grinding wheel assembly that is capable of grinding and-laterally sizing an elastomeric belt without accumulating and compacting fine particles of belt grindings between the belt and the side flanges. Ideally, such a grinding wheel assembly would be capable of expelling such swarf or grindings from the wheel as soon as they were produced in order to obviate the need for frequent cleaning operations. It would further be desirable if the abrasive inner surfaces of the flanges were capable of performing their lateral sizing operation with a minimum amount of friction in order to expedite production and prevent burn damage to the belt. Finally, it would be desirable if the abrasive coatings on the wheel flanges did not wear out any faster than the abrasive coating on the outer portion of the wheel in order to maximize the time between refurbishings and replacements.